| 摘要 |
PURPOSE:To obtain the title smooth board foam having improved physical properties, by means of a molding device of fan shape enlarging in the width direction of the material to be extruded provided at the tip of an extruder die. CONSTITUTION:A melt blend 10 prepared by kneading a thermoplastic resin with a volatile blowing agent with the screw 2 in the extruder 1 is passed through the die 3 attached to the extruder 1, the die lip 4, and the channel 11 of the molding device 5 of fan shape enlarging from the die lip 4 to the outlet in the width direction gradually, then molded and cooled while being foamed to give the molded article 12. EFFECT:A board foam having an expansion ratio of 10-40, a density of 0.026- 0.105g/cm<2>, uniform colsed cells with a cell diameter <= 1mm, and improved dimensional stability can be obtained. |
